This Core will establish a national inception cohort of 1000 rheumatoid arthritis (RA) patients seen by 100 randomly selected rheumatologists within their first year of disease and will follow these patients using standard ARAMIS protocols with full Health Assessment Questionnaire (HAQ) administration each six months. Compared with prior attempts at building RA inception cohorts, this study will be (1) much larger, (2) contemporary, (3) broadly representative, (4) ethnically diverse, (5) encompass alternative management strategies, (6) contain DNA typing data (DRBI *0401 and *0404), (7) include standardized central laboratory determination of CRP and Rheumatoid Factor, (8) be over-sampled for Black and Hispanic patients, (9) consist of consecutively seen patients without exclusions, and (10) be maintained for long-term follow-up, including standardized reading of hand radiographs at 4 years of disease. The Core task builds upon investigator and staff skills at physician and patient recruitment and in maintenance of large data sets over the long-term. This inception cohort will provide a unique and powerful resource in support of Projects 1 and 2 as well as for future studies.